None.
1. Field of the Invention
The present invention is for an outdoor electrical display sign, such as an LED or reflective sign, and more particularly, pertains to an outdoor electrical matrix display sign having an electrical resistance heating element on the transparent front panel of the sign, such as on the inside surface of the transparent front panel, for heating the surface of the transparent front panel for vaporizing of condensation or dissipating precipitation.
2. Description of the Prior Art
Prior art large outdoor electrical matrix display signs, such as signs at sporting events, shopping malls, and highway signs, have the propensity to have condensation buildup on the inside surface of the transparent front panel, such as for LED displays or reflective displays. This impairs the visibility of the display. Also, precipitation (e.g., sleet (ice), rain, snow, mist, frost) on the exterior surface of the transparent front panel impairs visibility of the display. In the past, it has been one practice to utilize an electrical resistance heater circulating hot air through the inside of the electrical sign for eliminating condensation or precipitation, but this reduces circuitry reliability.
The present invention overcomes the disadvantages of the prior art by providing an electrical resistance heating element on a surface of the transparent front panel of a large outdoor electrical matrix display sign.
The general purpose of the present invention is to provide a large outdoor electrical matrix display sign, such as an LED or reflective display contained within a housing which has a transparent front panel, generally formed of a transparent polymer, such as methyl methacrylate sold under the registered trademark PLEXIGLAS(copyright), with an electrical resistance heating element on the transparent front panel for eliminating condensation or dissipating precipitation from the transparent front panel. The electrical resistance heating element is adhesively secured onto or taped onto a surface of the transparent front panel, is laminated between the transparent front panel and an additional transparent polymer panel, is photoscreened or photo-etched onto a surface of the transparent front panel, or is formed by pouring electrical resistance material into minute grooves, such as V-grooves, formed in a surface of the transparent front panel, and is subsequently energized from an electrical power source, such as a low voltage direct current power source. The surface of the transparent front panel to which the electrical resistance heating element is applied may be either the inner surface or the outer surface.
According to one embodiment of the present invention, there is provided a large outdoor electrical display sign, which includes a housing, electrical display circuitry inside the housing, and a transparent polymer front panel over the display, the display being an LED, a reflective, or other electrical display device. An electrical resistance heating element is applied to the interior surface of the transparent front panel, such as by taping on or adhesively securing an electrical resistance heating element, by laminating the electrical resistance heating element between the transparent front panel and an additional transparent polymer panel, by photo-etching or photoscreening on an electrical resistance heating element, or by cutting minute grooves in the interior surface of the transparent front panel and then depositing an electrical resistance material. The electrical resistance heating element connects to a suitable electrical power source, such as a low voltage direct current source, such as a 12 volt direct current.
One significant aspect and feature of the present invention is an electrical resistance heating element on the interior surface of the transparent front panel of a large outdoor electrical matrix display sign to vaporize or dissipate any condensation or precipitation, such as a light coating of water vapor.
Having thus described embodiments and significant aspects and features of the present invention, it is the principal object of the present invention to provide a large outdoor electrical matrix display sign with an electrical resistance heating element on the transparent front panel thereof for eliminating condensation or dissipating precipitation.